2009

Biped and Physique
When the biped pelvis is selected in the viewports and
Attach To Node on
page 4671 is turned on, Physique traces its way from the pelvis down the legs
to the toes. From the pelvis it also traces its way up through the spine and
branches at the collar to the arms, hands, and fingers, and up the neck to the
head. A link and associated envelopes are created for each link found. If any
other objects, including 3ds Max bones, are linked to the biped, Physique
treats them similarly: it creates a link and envelopes.
When you use Physique to attach a mesh to the biped, remember this: If your
character has additional limbs, link 3ds Max bones to the biped for the extra
arms before using Attach To Node to create links and envelopes. When you
apply Physique using Attach To Node, it creates links and envelopes for all
the links in the biped, and for the linked bones. Link non-deformable objects
like a sword after using Attach To Node. That way the software doesn’t create
a link and envelopes for the sword.
Envelopes and Weighted Vertices
The Physique modifier uses envelopes as its primary tool for controlling skin
deformation. It also provides tendons and bulge angles for fine-tuning mesh
deformation after envelopes are adjusted. All envelopes have an inner and
outer bound (boundary). Vertices falling within the inner bound of a single
link receive a full weight of 1.0 from that link. Those falling outside the outer
bound receive no weight from that link. Vertices falling between the inner
and outer bounds receive a weight from 0 through 1.
Vertices move together with the link that influences them. Where multiple
envelopes encompass a vertex, that vertex receives weight from each envelope
and follows each link to an average position based on these weights. This
weighting from multiple links is considered blending. It is possible that weights
assigned to some vertices don’t reach a total weight of 1.0 or greater. Rather
than leaving these vertices behind, Physique by default normalizes them to
a value of 1.0.
Adjusting falloff, overlap, scale, and other envelope parameters changes vertex
weight distribution across links. This change, in turn, affects the way skin
behaves as the biped moves. By and large, you correct the way skin deforms
on a character by adjusting envelopes.
Deformable and Rigid Envelopes
There are two Envelope types per link,
deformable on page 7948 and rigid on
page 4628. Deformable envelopes follow the Physique deformation spline that
Understanding Physique | 4133